A man in Ho Chi Minh City was stabbed to death by his ex-wife's brother when he visited his son at the in-laws' on Wednesday.

Investigation found that Nguyen Trung Hieu, the 27-year-old father, had argued with the other man, Tran Minh Viet, who tried to prevent Hieu from seeing his son. During the argument Viet stabbed Hieu.

Viet has been arrested.

The couple divorced after Hieu rejected his wife's family tradition that the husband stays at the in-laws', doing housework, while the woman goes out to earn money. Their son is 17 months old, thus the wife won custody.

Before he died, Hieu made postings on different online forums sharing the difficulties he faced every time he went to visit his son, news website VnExpress reported.

On December 14, the father posted a video on YouTube as a diary for his son. A scene shows Hieu and his son separated by a door at his ex-wife's house, and the baby moving one hand through the door to touch his face.

Hieu had been attacked earlier by his ex-wife's family during a visit in October 2011, causing him to be hospitalized with brain injuries, one of Hieu's colleagues said in a forum.

The family of the wife even threatened to kill his parents if he continued to visit the boy, Hieu said.

Some people had advised Hieu to wait until the conflict subsided, but Hieu replied on the forum that "I tried, but after a couple days, I could not stand missing him "¦ I accepted to be beaten."

The father said he also started dating but then broke up with the girl because he did not feel right when he returned home and held his son.

Hieu's situation has won the sympathy of many Vietnamese Facebook users, who have set up a page called "Taking back the justice for the father killed when visiting his son."